The project demonstrates an ultra-high resolution x-ray imaging system. It provides high contrast images of the density structure of objects that are otherwise x-ray transparent, e.g. low-Z human soft-tissue, and obtains edge enhanced contrast from x-ray refractive-index gradients. In mammography the contrast of a microcalcification is increased typically by 4-fold, and cancerous masses by much more. The system can be tuned to obtain element selective contrast to image resonantly minute quantities of a tracer element with Z=35-56, and only that element. It virtually eliminates the blurring and contrast-reducing effects of x-ray scatter. It operates at 15-40keV average x-ray energy with 3-50- fold reduced patient dosage, and significantly reduces the scanning time for CT 3D-imaging. It uses physical optics principles to form a Talbot-Lau imaging x-ray interferometer. It uses a conventional x-ray tube and filter, two microfabricated x-ray diffraction gratings, a CCD detector (and/or film), and an in-situ laser interferometer for alignment. Phase-I demonstrates a scatter-free 3cmx3cm image at - 50micrometers resolution, with refractive-index and/or tracer imaging. Phase-II similarly obtains >10cmx10cm images with an engineering prototype for a marketable device.